Previous processes for identifying multiple individual loads supplied by a common AC power service use measurements of electrical parameters of only the common supply. These parameters are digitally measured for each alternating current (AC) supply cycle, e.g., 60 samples per second in North America. The loads are identified using the time dependent behaviors (referred to herein as time traces) of the first few seconds of the turn-on positive transition of these parameters. Many conventional devices such as incandescent lights and heaters consume essentially constant power after the positive transition until the device is turned off, thus producing a negative transition. Provided none of the transitions occur too close together, the on-off state of multiple devices can be accurately determined, as well as the power, runtime, and energy consumed by each device. This process is referred to herein as a time trace disaggregation process (TTDP).
Residential service is typically split single-phase where the voltage on each supply leg is 180 degrees out of phase relative to neutral. Commercial service is typically three-phase where the voltage on each supply leg is 120 degrees out of phase relative to the other supply legs. Devices that use the most power connect to multiple phases so that current flows directly between service legs rather than through neutral. These devices are generally referred to herein as multi-phase devices.
Since multi-phase loads are between service legs, the power and current transitions occur at the same time and change in current flow is the same in both legs. These characteristics makes it possible to differentiate singe-phase transitions from multi-phase transitions. Likewise, single-phase instances and devices can be processed separately from multi-phase instances and devices. This additional differentiation improves the accuracy of identification and tracking of the multiple different devices found in typical residential and commercial buildings.